Today, Daily Development talks to Roger-Mark De Souza, Director of Population, Environmental Security and Resilience at the Wilson Centre, about the impact the world’s growing population will have on the environment.

DD: Do you think that the world’s increasing population is the main cause of all environmental problems?

DS: The relationship between population dynamics and environmental change is not a simple linear equation, but instead a complex system of interrelationships. As Laurie Mazur writes on our blog, New Security Beat, nonlinear effects, including thresholds and feedbacks, can amplify the environmental impact of human numbers: “A species may depend on a certain amount of intact habitat to survive. As human settlements encroach, a threshold is eventually crossed, and the species will, sometimes quite suddenly (within a generation or two), collapse.”

But it would be untrue to say demographic pressures cause all environmental problems. Rapid population growth tends to affect local resource scarcity first (e.g. deforestation, water and land use, fisheries), while consumption is the driver of many other types of environmental issues.

So both population, consumption and how exactly something is produced (is it produced ethically, locally, efficiently?) are all important. It is also important to remember that in the parts of the world that are still growing rapidly, people are generally more reliant on their local natural resources than elsewhere. Sub-Saharan Africa and parts of the Middle East and South Asia, where population growth is rapid, are disproportionately reliant on subsistence farming, which requires land and water, resources that can be quickly depleted by growth. This creates unique vulnerabilities and is an impetus for addressing population and environment issues together. 

DD: What are the long-term environmental repercussions of Africa’s demography?

DS: The long-term repercussions of Africa’s demography are very significant. According to the latest United Nations population projections, three out of four people added to the world population between now and the end of the century will be born in sub-Saharan Africa. Nigeria alone could be home to 730 million people, while other countries could be many times their current sizes.

When it comes to the environment, this kind of growth brings to mind the kind of local resource scarcity I talked about above. Water, land, forests, fish and food may be more scarce at local levels. People may also move to avoid such scarcity, creating pressure in cities or other countries, which may lead to tension or simply more scarcity somewhere else.

The interaction between rapid population growth and climate change is also crucial. For example, as more people move to coastal cities—Africa is now urbanizing faster than nearly anywhere else—that may create pockets of vulnerability to things like sea-level rise, storm surge and extreme weather events. Subsistence farming too may become less viable, which when combined with more mouths to feed and less arable land per capita, could make food security a much greater challenge.

For example, Kathleen Mogelgaard has written on New Security Beat about how climate change is currently projected to impact maize yields in Malawi. She notes that the productivity of maize, the major national crop, is projected to decline by 20% by 2030, while the population is projected to grow from 15 million people today to between 45 and 55 million by mid-century, all while one in five children are already undernourished. 

The mathematics of population growth mean that much of the near-term growth is basically locked in, which may seem scary, but the good news is that longer-term projections, like those that reach out to 2100, are much less certain at this stage. History has shown that when women are given the opportunity and means to control their own fertility, they tend to have fewer children. Governments and civil society organizations have an opportunity to start making contraception and basic reproductive health services more widely available across the continent and significantly change those long-term projections.

DD: How can we encourage African governments to pay attention to environment issues?

DS: Many African governments are concerned about population growth—Ethiopia, Rwanda and Kenya, to name a few, have national population policies in place that emphasize expanding health care to rural and underserved areas.

Environmental issues too are on the radar of many governments. Climate change is certainly becoming a more major part of all kinds of development programming—both efforts by local governments and international aid. Many African leaders may see natural resource extraction as a natural path towards development, but it’s important that the long-term view is emphasized.

Studies have shown that climate change combined with resource scarcity have exacerbated tensions in many parts of Africa, leading to violent conflict in some places. The United Nations Environment Programme has shown the adverse effects of contaminated water and air on human development. According to its research, a full 28% of Africa’s disease burden is the result of environment factors.

These are all very compelling reasons why every government, and especially African governments, should pay attention to environmental issues. Environmental conflict research has shown that more inclusive decision-making by governments can go a long way towards preventing violent conflict between groups that face scarcity or changes in their natural resource bases—changes we know are already happening in Africa. Likewise, clean water and air and equitable development of natural resources are prerequisites for the kind of broad-based development that Africa needs to prosper.